Millenium RAT vs ToxicEye RAT
Understanding the connection — shared architecture, modules, and code organization that suggest lineage or derivation.
Is Millenium RAT related to ToxicEye? CYFIRMA's 2023 analysis identified extensive structural similarities between early Millenium RAT and the older ToxicEye Telegram RAT, including architecture, modules, code organization, namespaces, function names, arguments, and functionality. This evidence suggests lineage or derivation — not definitive proof of identical authorship. The newest native-C++ 4.x branch is not simply identical to earlier ToxicEye code.
What CYFIRMA observed
In its November 2023 analysis, CYFIRMA identified extensive structural similarities between Millenium RAT and the older ToxicEye Telegram RAT. The similarities reportedly included:
- ▸ Architecture
- ▸ Modules
- ▸ Code organization
- ▸ Namespaces
- ▸ Function names and arguments
- ▸ Functionality
This is described as evidence suggesting lineage or derivation — not definitive proof of identical authorship. Shared code structure can result from reuse, fork, inspiration, or common templates.
Why the 4.x branch changes the picture
The native C++ 4.x branch is a substantial rewrite. Malware families can undergo major rewrites while retaining operational concepts (Telegram C2, information stealing, remote control). Do not claim the newest branch is simply identical to earlier ToxicEye code.
- 01ToxicEye: older Telegram RAT
- 02Millenium 2.x: strong structural similarity (CYFIRMA)
- 03Shared: architecture, modules, namespaces, functions
- 04Interpretation: lineage / derivation, not proof
- 05Millenium 4.x: native C++ rewrite — not identical
Comparison table
| Attribute | ToxicEye | Millenium RAT 2.x | Millenium RAT 4.x |
|---|---|---|---|
| Windows targeting | Yes | Yes | Yes |
| Telegram-based C2 | Yes | Yes | Yes (libcurl) |
| Implementation language | .NET | .NET | Native C++ |
| Information stealing | Yes | Yes | Yes (expanded) |
| Remote-control functionality | Yes | Yes | Yes |
| Active development status | Older | Superseded | Active |
| Architecture | .NET | .NET | Native C++ rewrite |
- ▸Early Millenium RAT shares extensive structure with ToxicEye (CYFIRMA).
- ▸Shared code suggests lineage or derivation — not proof of identical authorship.
- ▸The 4.x native C++ branch is a substantial rewrite, not identical code.
- ▸Malware families can retain operational concepts across major rewrites.
